title: Effectiveness of rump-mounted devices and androgenized females for detection of estrus in dairy cattle.
abstract: Detection of estrus was evaluated in 1124 estrous cycles for the effectiveness of rump-mounted devices and androgenized females equipped with chin-ball markers. Estrous number, location, type of detection method (compared with visual observation of estrus), and milk progesterone influenced standing behavior. Rates of disagreement with visual observation of estrus were 13.2, 17.0, and 18.5% for Kamar, Hot Flash, and the two devices used simultaneously. Frequency of observed standing behavior was greater with fourth and subsequent estrous periods. Percentage of high milk progesterone during suspected estrus for cows inseminated was 3.8% for controls, 11.0% for Kamar cattle, 18.5% for Hot Flash cattle, and 12.6% when both devices were used. Androgenized cattle equipped with chin-ball markers marked 47% of the cattle observed in estrus but no cows with high milk progesterone. Combination of rump-mounted devices and androgenized females increased the percentage of estrous detection by 1.3 to 6.2% compared with device or androgenized female used alone. Loss rates of rump-mounted devices exceeded 40%. High milk progesterone at estrus was associated with lower fertility.
authors.affiliation: Virginia Agricultural Experiment Station, Virginia Polytechnic Institute and State University, Blacksburg 24061.
authors.forename: F C
authors.initials: FC
authors.lastname: Gwazdauskas
authors.forename: R L
authors.initials: RL
authors.lastname: Nebel
authors.forename: D J
authors.initials: DJ
authors.lastname: Sprecher
authors.forename: W D
authors.initials: WD
authors.lastname: Whittier
authors.forename: M L
authors.initials: ML
authors.lastname: McGilliard
mesh_terms: D000728:Androgens / Q000008:administration & dosage; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004972:Estrus Detection / Q000379:methods*; D005069:Evaluation Studies as Topic; D005260:Female; D005306:Fertilization; D007315:Insemination, Artificial / Q000662:veterinary; D008892:Milk / Q000737:chemistry; D011374:Progesterone / Q000032:analysis
chemical_list: D000728:Androgens; D011374:Progesterone